The present invention relates to the field of cooling systems in computer systems. More specifically, the present invention relates to cooling ducts that direct air drawn from outside the computer system to electronic components in the computer system.
The current generation of central processing units (CPUs) and its components, collectively known as Processor Core Logic (PCL) components, generate a significant amount of heat during operation. If the heat generated by the PCL components is not properly dissipated, then the heat builds up and raises the temperature of the PCL components beyond their recommended operating temperatures. This adversely affects the performance of the PCL components. Various devices have been implemented to keep PCL components at their recommended operating temperatures by transferring or dissipating heat generated by the PCL components away from the PCL components.
One known approach is to purge heated air from within the computer system chassis with an axial fan mounted to the rear of the computer system chassis in the vicinity of the PCL component area. Commonly, the purging rear fan operated in series with a power supply fan both acting as an air exchanger. In order to further facilitate heat dissipation, an active fan heat sink is attached to the processor. The active fan heat sink is commonly in the form of an axial fan attached to the processor generating airflow onto the processor, thereby force-cooling the processor. Force-cooling involves cooling a specific component by directly applying air onto and across the surface of the component. High velocity air applied to the surface of the component raises the convective heat transfer coefficient of the surface of that component, thereby increasing convection cooling with respect to that component. Air exchange cooling involves replacing heated air in a first location, such as inside a chassis of the computer system, with cooler air from a second location, such as outside the chassis.
As the number of fans increases to reduce the heat generated from the PCL components, the cost and acoustic noise of the computer system increases. Additionally, as the number of fans increases, the energy efficiency decreases due to the power required to run the fans.